The aim of this study was to determine the allelopathic effect of common ragweed (Ambrosia artemisiifolia L.) on germination and growth of weed species velvetleaf (Abutilon theophrasti Med.), redroot pigweed (Amaranthus retroflexus L.) and scentless chamomile (Tripleurospermum inodorum (L.) C.H. Schultz.). Under laboratory conditions, the effects of water extracts of dry aboveground biomass of ragweed in concentrations of 1, 5 and 10% were evaluated in Petri dishes, while the impact of ragweed plant residues at doses of 10, 20 and 30 g/kg soil were examined in the experiment with pots. In Petri dishes, weed germination was inhibited up to 100%. Likewise, the negative impact of higher concentrations was recorded on seedling length and fresh weight. Scentless chamomile was the most sensitive to applied extracts. Incorporation of plant residues into the soil significantly reduced only emergence of velvetleaf for 38.9%. Higher doses had inhibitory effect on seedling length of redroot pigweed and scentless chamomile, and the fresh weight of velvetleaf. The effect of extracts in Petri dishes was stronger than the impact of plant residues in pots.